mybatis基于注解实现简单的账户的增删改查（CRUD）

项目结构

导入maven坐标

    <dependencies>
<!--        mybatis框架-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.4</version>
        </dependency>

<!--        连接数据库-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.48</version>
        </dependency>

<!--        测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>

创建账户表

create table account(
	id int primary key auto_increment,
	name varchar(40),
	money float
)character set utf8 collate utf8_general_ci;

insert into account(name,money) values('aaa',1000);
insert into account(name,money) values('bbb',1000);
insert into account(name,money) values('ccc',1000);

实体类Account.java

package com.cenzn.domain;

public class Account {

    private Integer id;
    private String name;
    private Float money;
	
	//Setter
	//Getter
	//toString
}

mybatis常用注解

@Insert:实现新增
@Update:实现更新
@Delete:实现删除
@Select:实现查询
@Result:实现结果集封装
@Results:可以与@Result 一起使用，封装多个结果集
@ResultMap:实现引用@Results 定义的封装
@One:实现一对一结果集封装
@Many:实现一对多结果集封装
@SelectProvider: 实现动态 SQL 映射
@CacheNamespace:实现注解二级缓存的使用

业务层接口类Account.java

package com.cenzn.dao;

import com.cenzn.domain.Account;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import java.util.List;

public interface IAccountDao {

    /**
     * 查询所有账户
     * @return
     */
    @Select("select * from account")
    public List<Account> findAccountAll();

    /**
     * 保存账户
     * @param account
     */
    @Insert("insert into account(name,money)values(#{name},#{money})")
    public void saveAccount(Account account);


    /**
     * 更新账户
     * @param account
     */
    @Update("update account set name = #{name},money=#{money} where id =#{id}")
    public void updateAccount(Account account);

    /**
     * 删除账户
     * @param accountId
     */
    @Select("delete from account where id = #{accountId}")
    public void deleteAccout(Integer accountId);

}

mybatis配置xml文件

<configuration>
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC">transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///spring"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            dataSource>
        environment>
    environments>


    <mappers>
        <mapper class="com.cenzn.dao.IAccountDao"/>
    mappers>
configuration>

测试

由于每个测试都有一部分相同的代码提到类的开头

    private InputStream in;
    private SqlSessionFactoryBuilder builder;
    private SqlSessionFactory factory;
    private SqlSession session;
    private IAccountDao accountDao;

	//方法开始之前执行
    @Before
    public void init() throws IOException {
        System.out.println("================init================");
        //1.读取配置文件
        in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建 SqlSessionFactory 的构建者对象
        builder = new SqlSessionFactoryBuilder();
        //3.使用构建者创建工厂对象 SqlSessionFactory
        factory = builder.build(in);
        //4.使用 SqlSessionFactory 生产 SqlSession 对象
        session = factory.openSession(true);//true自动提交事务
        //5.使用 SqlSession 创建 dao 接口的代理对象
        accountDao = session.getMapper(IAccountDao.class);

    }
	//方法结束之后执行
    @After
    public void destroy() throws IOException {
        System.out.println("================destroy================");
        in.close();
        session.close();

    }

查找所有

    @Test
    public void findTest(){
        List<Account> accounts = accountDao.findAccountAll();
        for (Account account : accounts){
            System.out.println(account);
        }
    }

运行结果

保存账户

    @Test
    public void saveTest(){
        Account account = new Account();
        account.setName("ddd");
        account.setMoney(1234f);
        accountDao.saveAccount(account);
    }

运行结果

更新账户

    @Test
    public void UpdateTest(){
        Account account = new Account();
        account.setId(4);
        account.setName("ddd");
        account.setMoney(12345f);
        accountDao.updateAccount(account);
    }

运行结果

删除账户

    @Test
    public void DeleteTest(){
        accountDao.deleteAccout(4);
    }

运行结果